Abstract: Four kinds of commonly used CNOOC SBS modified asphalt were prepared from CNOOC 36-1 asphalt. The penetration at 25℃，ductility, softing point and PG high temperature parameters of the 4 samples were investigated by conventional penetration tests and DSR tests under multi-temperature conditions. Based on the test results, a relationship between penetration grade and performance high temperature grade PG was established. The correlation coefficient of the relational is >0.99. When PG level reaches 76 ℃, the 25 ℃ penetration result should not exceed 66.5; When PG level reaches 82 ℃, the 25 ℃ penetration should not exceed 63.0. The PG high temperature levels can well be estimated according to the penetration grade.

Key words: modified asphalt, penetration, PG grade, CNOOC